1. Technical Field
Several aspects of the present invention relate to an electrophoretic display device, a method of manufacturing an electrophoretic display device and an electronic device, and more specifically relates to an electrophoretic display device, a method of manufacturing the electrophoretic display device, and an electronic device provided with the electrophoretic display device.
2. Related Art
It is generally known that, if electric fields are allowed to act on a dispersion system in which fine particles are dispersed in liquid, the fine particles move (or migrate) in the liquid by the Coulomb force. This phenomenon is referred to as electrophoresis. In recent years, an electrophoretic display device that displays desired information (images) using the electrophoresis draws attention as a new display device.
The electrophoretic display device is characterized by exhibiting display memory characteristics and broad viewing angle characteristics even at the time of stoppage of voltage application and by possessing a capability of performing high contrast display with reduced electricity consumption.
An electrophoretic display device is a non-luminous type (reflection type) display device. Therefore, the electrophoretic display device has characteristic that scarcely damage eyes as compared to a luminous type display device such as a cathode-ray tube display.
As such an electrophoretic display device, there is known a microcapsule-type electrophoretic display device that includes a pair of substrates each having an electrode, and a plurality of microcapsules arranged between the substrates and filled with a dispersion system in which electrophoretic particles (fine particles) are dispersed in a dispersion medium (JP A-2007-58151 is an example of the related art).
In the meanwhile, in principle, an electrophoretic display device is characterized by its reduced electricity consumption characteristic as described above. On the other hand, however, a phenomenon that leak current flows between electrodes is likely to occur. When such a phenomenon occurs, electric power is consumed due to the leak current. Therefore, there is a problem that electricity consumption increases.
That is to say, in the case where a voltage V to be applied to between the electrodes is constant, electricity consumption P of the electrophoretic display device is inversely proportional to resistance values R between the electrodes as represented by the following relation: P=V2/R.
Therefore, in a conventional electrophoretic display device, insulation property between electrodes is ensured by a binder having insulation property which is filled in spaces between the electrodes. However, metal ions and the like, which can not be removed from the binder, are contained in the binder.
Therefore, resistance values R of the binder are decreased due to the metal ions, so that there is a problem that electricity consumption P of the conventional electrophoretic display device is extremely increased.
Further, in order to suppress the electricity consumption P of the conventional electrophoretic display device from being increased, it may be conceived that a voltage V to be applied to between the electrodes is lowered. In this case, however, electric fields having sufficient intensity can not act on electrophoretic particles sufficiently so that it is impossible to move electrophoretic particles.